10 February 2026
LGOIMA 26-001 and 002
Sam Brown
[email address]
Tēnā koe Sam
Wellington Water telecommunications infrastructure
This letter responds to your two related requests for official information, referenced LGOIMA
26-001 and LGOIMA 26-002, which concern Wellington Water Limited’s operational
telecommunications and SCADA connectivity.
Your request numbered 26-002 was originally made to Greater Wellington Regional Council and
was transferred to Wellington Water Limited for response under section 14 of the Local
Government Official Information and Meetings Act 1987 (LGOIMA).
Given the significant overlap in subject matter between the two requests, Wellington Water has
provided a single consolidated response to avoid duplication and to ensure clarity and
consistency.
Wellington Water has considered each aspect of your requests. Information has been released
where appropriate, and information has been withheld only where its release would be likely to
prejudice the public interest, for the reasons set out below.
Where information is addressed at a high level rather than in response to individual questions,
this reflects the consolidated nature of this response and the need to manage the risks
associated with cumulative disclosure of sensitive operational information.
Scope and timeframe
This response relates to Wellington Water’s operational water and wastewater infrastructure
that requires telecommunications or data connectivity for operational purposes. This includes
treatment plants, major and remote pumping stations, reservoirs and storage facilities,
telemetry-enabled water meters, and sensors and monitoring devices used to support network
operations.
Office buildings and general corporate IT infrastructure are excluded.
The information provided reflects arrangements current as at December 2025, and connectivity
contracts or arrangements entered into or renewed between 2022 and 2025, where applicable.
Operational telecommunications overview
Wellington Water operates a dedicated operational telecommunications network to support
SCADA (Supervisory Control and Data Acquisition) communications for essential water,
wastewater, and stormwater services on behalf of its client councils. The primary purpose of
this network is to enable real-time monitoring, control, and alarm management of critical
infrastructure.
Operational connectivity is delivered through a combination of technologies, selected based on
asset type, location, criticality, and resilience requirements. These include:
Digital radio telemetry systems, supporting several hundred Remote Terminal Units
(RTUs) deployed across water, wastewater, and stormwater assets. RTUs communicate
with radio base stations using licensed UHF and VHF frequencies.
Microwave radio links, a number of microwave radio links forming the primary data
trunk network connecting radio base stations to SCADA servers. This network is
designed in resilient ring configurations to enable continued operation in the event of a
single link failure.
Cellular and wireless services, used primarily for remote assets, telemetry-enabled
meters, and low-bandwidth monitoring devices.
Limited fibre connectivity, used selectively within the Secondary SCADA environment
(SecureWAN) where this represents the most appropriate and resilient solution for
specific operational sites.
All primary SCADA sites are owned by the respective client councils and are utilised by
Wellington Water for operational purposes. A single exception exists within the Secondary
SCADA (SecureWAN) environment, where equipment is located on a third-party site.
Operational telecommunications infrastructure is delivered through a mix of Wellington Water-
managed and provider-managed arrangements. Primary SCADA radio and microwave
infrastructure is operated and maintained by Wellington Water’s in-house automation and
control systems teams. Certain secondary or ancillary connectivity services, including
SecureWAN and cellular telemetry components, are delivered under contract by network
service providers.
Resilience and continuity of essential services are key design principles across the operational
network. Higher-criticality assets, such as treatment plants and major pumping stations, are
supported by higher-availability connectivity and, where appropriate, primary and secondary
paths. Key SCADA and telecommunications sites are equipped with backup power systems,
designed to support continued operation during extended power outages.
Contracts, expenditure, and renewal
Operational connectivity services are procured through a combination of direct contracts with
telecommunications and network service providers, as well as connectivity components
embedded within broader operational or technology service contracts (such as metering and
monitoring arrangements).
For the 2024/25 financial year, Wellington Water’s total expenditure on operational connectivity
services was in the order of several million dollars, inclusive of telecommunications services,
network service provision, and connectivity components embedded within operational
technology contracts.
Contract terms vary by service type. Shorter-term arrangements of one to three years are
common for some cellular and telemetry services, while longer-term arrangements apply to
core operational networks. Renewal and review cycles are deliberately staggered to manage
operational risk and avoid simultaneous expiry across critical services.
The SecureWAN network is maintained under a lease arrangement currently due to expire on 1
June 2026. Wellington Water expects to review this arrangement to determine appropriate next
steps. In addition, Wellington Water is planning future renewal of data trunk microwave
hardware as part of its ongoing asset management and lifecycle planning.
Information withheld
Some information requested has been withheld under section 7(2)(c)(ii) of LGOIMA, where
release would be likely to prejudice the public interest by exposing sensitive operational
arrangements relating to essential water and wastewater services.
Information withheld includes:
lists of radio communications sites and site locations;
detailed network maps or topology diagrams identifying specific site connections,
routing, or provider allocation;
radio and microwave frequency information;
copies of individual contracts, detailed contractual schedules, and provider-by-
provider expenditure breakdowns;
technical details that would enable inferences about network vulnerabilities, critical
dependencies, or points of disruption.
In applying this withholding ground, Wellington Water has had regard to the cumulative effect of
disclosure. While individual items of information may appear benign in isolation, their
combined release could materially reduce the effort required to identify or exploit
vulnerabilities within critical infrastructure. This approach is consistent with established risk-
management principles for essential services and with Ombudsman guidance on the
protection of sensitive operational information.
Public interest considerations
Wellington Water has carefully weighed the public interest in transparency and accountability
against the need to protect the security and resilience of essential water and wastewater
services. We consider that the information released provides meaningful insight into how
operational telecommunications enable essential services, while the information withheld is
necessary and proportionate to protect the security, resilience, and continuity of essential
services.
Please note that it is our policy to proactively publish responses to official information requests
where possible. As such, this response may be published on our website at
www.wellingtonwater.co.nz/about-us/official-requests/official-information-act-responses,
with any personal information removed.
You have the right to seek an investigation and review of this response by the Ombudsman.
Information about how to make a complaint is available at www.ombudsman.parliament.nz or
by calling 0800 802 602.
If you would like to discuss this response, please contact us at
[Wellington Water Limited request email]
Nāku noa, nā
Jeremy McKibbin
Group Manager
Treatment and Control Systems
